JMP's < operator can compare multiple values strung together:
date = 6aug2018;
if ( 1jan2018 < date < 1jan2019, "good", "bad");
"good"
If your data has missing values, you'll need to test for them. If statement blog.
update: here is an example, look for
target > now > target - In Hours( 100 )
about half way down. change the target to target = today()+100; to see the effect.
Craige